The 23mm is a really good lens, the build and image quality is outstanding. I would say that if you have the X100 or X100S in addition to another Fuji, you don't really need this lens, and the price difference is small. That said, that beautiful f/1.4 can be really handy at times.

The aperture ring is much better than on the 35mm. It feels better, more expensive and it is a lot harder to accidently bump. The manual focus is nice, you have to pull the focus ring back to enable it and it gives you all the focus scale you need. The only thing is that the camera (X-E2) stays in manual focus while the ring is pulled back, and it caught me out once or twice. It is heavier than the 35mm and a bit bulkier.